Overall, new manufacturing systems are anywhere from 1,000 to one
million times bigger consumers of energy, per pound of output, than
more traditional industries. In short, pound for pound, making
microchips uses up orders of magnitude more energy than making manhole
covers.

At first glance, it may seem strange to make comparisons between
such widely disparate processes as metal casting and chip making. But
Professor Timothy Gutowski of MIT's Department of Mechanical
Engineering, who led the analysis, explains that such a broad
comparison of energy efficiency is an essential first step toward
optimizing these newer manufacturing methods as they gear up for
ever-larger production.

"The seemingly extravagant use of materials and energy resources by
many newer manufacturing processes is alarming and needs to be
addressed alongside claims of improved sustainability from products
manufactured by these means," Gutowksi and his colleagues say in their
conclusion to the study, which was recently published in the journal Environmental Science and Technology (ES&T).

Gutowksi notes that manufacturers have traditionally been more
concerned about factors like price, quality, or cycle time, and not as
concerned over how much energy their manufacturing processes use. This
latter issue will become more important, however, as the new industries
scale up -- especially if energy prices rise again or if a carbon tax
is adopted, he says.

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Solar panels are a good example. Their production, which uses some
of the same manufacturing processes as microchips but on a large scale,
is escalating dramatically. The inherent inefficiency of current solar
panel manufacturing methods could drastically reduce the technology's
lifecycle energy balance -- that is, the ratio of the energy the panel
would produce over its useful lifetime to the energy required to
manufacture it.